Speaker
Description
The ARC tokamak is a compact, high-field fusion pilot plant being designed by Commonwealth Fusion Systems to produce net electricity with high-temperature superconducting magnets. It uses a molten salt, FLiBe blanket for tritium breeding and heat removal in a simplified, high-performance design.
We present a multiphysics digital engineering workflow that integrates mesh-based Monte Carlo neutronics (MCNP6) with ANSYS CFD to support increasingly detailed design of ARC’s blanket, vessel, and coolant systems. The workflow couples nuclear heating maps from MCNP6 with thermal–hydraulic simulations: heating distributions inform FLiBe flow requirements, while CFD returns temperature and velocity fields that guide material selection, structural optimization, and flow path design. Beyond heat transport, the workflow also models the generation and circulation of activation products within the FLiBe, particularly important isotopes such as N-16, F-18, F-20, and O-19. These short-lived radionuclides create a moving source term that extends outside the tokamak into the balance-of-plant, particularly at heat exchangers with the secondary nitrate salt loop. By linking neutronics with CFD, the workflow enables steady-state mapping of isotope distributions and the resulting dose fields throughout the facility. Since activated salt requires radiation shielding and contributes significantly to the plant’s external source term, it is advantageous to minimize radionuclide concentrations leaving the vessel. The workflow addresses this optimization challenge by providing a means to evaluate and design flow paths that maximize in-vessel decay before the coolant exits the machine.
This paper describes the architecture of the data exchange and solver coupling, and presents preliminary results that highlight the potential of integrated multiphysics workflows to accelerate fusion power plant design while providing a more complete picture of nuclear heating, coolant performance, and radiological safety.
| Country or International Organisation | United States of America |
|---|---|
| Affiliation | Commonwealth Fusion Systems |
| Speaker's email address | acarter@cfs.energy |
